1. Field of the Invention
The present invention relates to a power supply control device for an electronic equipment, and more particularly, to a power supply control device for an electronic equipment having a key-off function that controls a voltage to be supplied to the electronic equipment.
2. Description of the Related Art
A printer is a machine that prints printing data received from a computer connected to the printer and data of the printer on recording paper using ink or toner and then outputs the data. Such a printer is used only when performing a printing operation with respect to the printing data. When the printer does not perform the printing operation in the power-on state, unnecessary power consumption occurs.
A conventional printer is continuously supplied with a predetermined amount of power even in a turned-off state. Accordingly, when printing work is not being performed, the printer is switched to a sleep mode in which the printer is supplied with a lower voltage than required for the printing work in order to decrease the power consumption. However, the power consumption still occurs even in the sleep mode.
In order to solve the above problem, two ways of turning on a primary power supply of a power supplier automatically have been proposed. One way is that a user turns on a power key, and the other way is that a printer system supplies a power-on signal to the power supplier. When a user turns off the power-key, the power supplier is actually turned-off by a power-off signal of the printer system.
However, if an error occurs in the printer system, the power-off signal may not be transmitted and thus, the power supplier is not turned-off even when a user wishes to turn the power supplier off using the power key. In such case, disconnecting an AC power cord from an AC power source is necessary to turn off the printer. Accordingly, there is an inconvenience in using the printer.